Process for making improved zeolite catalysts from peptized aluminas

Abstract

This invention relates to a process of preparing a catalyst from zeolite and peptized alumina. The invention comprises adding a yttrium compound to the zeolite, either prior to, during, or after its combination with the peptized alumina. The yttrium compound can be added to the zeolite via exchange of yttrium onto the zeolite prior to addition of peptized alumina, or the yttrium can be added as a soluble salt during the combination of the zeolite and peptized alumina. In either embodiment, the zeolite catalyst is then formed from the zeolite, yttrium and peptized alumina, optionally containing other inorganic oxide. This invention is suitable for preparing fluid cracking catalysts.

What is claimed is: 
     
       1. A process for making a catalyst, the process comprising (a) combining peptized alumina, yttrium compound, and zeolite having catalytic activity in a fluid catalytic cracking process, and (b) forming an alumina-containing catalyst from the combination in (a),
 wherein the yttrium compound is present in an amount ranging from about 0.5% to about 15% by weight, measured as an oxide (Y 2 O 3 ) of the zeolite, and 
 wherein the zeolite is faujasite, 
 the yttrium compound is located within pores of the zeolite, and 
 a rare earth is present with a ratio of the rare earth to the yttrium compound in a range of not more than 0.5. 
 
     
     
       2. A process according to  claim 1  wherein the peptized alumina is based on hydrated alumina. 
     
     
       3. A process according to  claim 1  wherein the peptized alumina is based on pseudoboehmite or boehmite. 
     
     
       4. A process according to  claim 1  wherein the peptized alumina is formed using acid selected from the group consisting of formic acid, nitric acid, acetic acid, hydrochloric acid, and mixture thereof. 
     
     
       5. A process according to  claim 1  wherein alumina and acid are combined with an acid stable zeolite having catalytic activity in a fluid catalytic cracking process, wherein the alumina and the acid stable zeolite are combined under conditions sufficient to form peptized alumina in the presence of the yttrium compound and the acid stable zeolite. 
     
     
       6. A process according to  claim 1  wherein the alumina-containing catalyst is formed by spray drying the combination in (a). 
     
     
       7. A process according to  claim 6  wherein the spray drying is conducted at an inlet temperature in the range of 220° C. to 540° C. 
     
     
       8. A process according to  claim 6  wherein the alumina-containing catalyst is in the form of particulate having an average particle size in the range of 20 to 150 microns. 
     
     
       9. A process according to  claim 1  wherein the yttrium compound is an yttrium salt soluble in water or in acid. 
     
     
       10. A process according to  claim 1  wherein the yttrium compound is selected from the group consisting of yttrium halide, yttrium nitrate, yttrium carbonate, yttrium sulfate, yttrium oxide and yttrium hydroxide. 
     
     
       11. A process according to  claim 1  wherein the yttrium compound further comprises rare earth in a ratio by weight of rare earth oxide to yttrium oxide in the range of 0.01 to 1. 
     
     
       12. A process according to  claim 1  wherein the zeolite is zeolite Y. 
     
     
       13. A process according to  claim 1  wherein the zeolite is zeolite USY. 
     
     
       14. A process according to  claim 1  wherein the catalyst contains essentially no divalent metal. 
     
     
       15. A process according to  claim 1  wherein the yttrium and the zeolite are added to the combination in (a) as yttrium cation exchanged on the zeolite. 
     
     
       16. A process according to  claim 15 , wherein the yttrium exchanged zeolite is dried and calcined in the presence of steam. 
     
     
       17. A process according to  claim 1  wherein the combination in (a) further comprises inorganic oxide other than alumina. 
     
     
       18. A process according to  claim 17  wherein the inorganic oxide is selected from the group consisting of clay, silica, silica alumina, and bulk alumina. 
     
     
       19. A method of reducing loss of zeolite surface area in a zeolite containing catalyst prepared from peptized alumina and in a form suitable for fluidized catalytic cracking, the method comprising
 (a) forming peptized alumina, 
 (b) adding yttrium compound to a zeolite having catalytic activity in a fluid catalytic cracking process, 
 (c) adding peptized alumina to the zeolite before, during, and/or after addition of the yttrium compound to the zeolite, and 
 (d) forming a catalyst suitable for fluidized catalytic cracking, 
 wherein the yttrium compound is present in an amount ranging from about 0.5% to about 15% by weight, measured as an oxide (Y 2 O 3 ) of the zeolite, and 
 wherein the zeolite is faujasite, 
 the yttrium compound is located within pores of the zeolite, and 
 a rare earth is present with a ratio of the rare earth to the yttrium compound in a range of not more than 0.5. 
 
     
     
       20. A method according to  claim 19  wherein the peptized alumina is formed using an acid. 
     
     
       21. A method according to  claim 20  wherein the acid is selected from the group consisting of formic acid, nitric acid, acetic acid, hydrochloric acid, and mixture thereof. 
     
     
       22. A method according to  claim 19 , wherein the yttrium and the zeolite are processed to produce yttrium exchanged zeolite, and the peptized alumina in (c) is added after the yttrium is exchanged onto the zeolite. 
     
     
       23. A method according to  claim 22 , wherein the yttrium exchanged zeolite is dried and calcined in the presence of steam prior to addition of peptized alumina. 
     
     
       24. A method according to  claim 19  wherein the peptized alumina is based on hydrated alumina. 
     
     
       25. A method according to  claim 19 , wherein the peptized alumina is based on pseudoboehmite or boehmite. 
     
     
       26. A method according to  claim 19  wherein the yttrium compound further comprise rare earth in a ratio by weight of rare earth oxide to yttrium oxide in the range of 0.01 to 1. 
     
     
       27. A method according to  claim 17  wherein the catalyst suitable for fluidized catalytic cracking is formed by spray drying. 
     
     
       28. A method according to  claim 27  wherein the catalyst suitable for fluidized catalytic cracking has an average particle size in the range of 20 to 150 microns.